Amplification system for glow relay devices



De c. 4, 1934. H. c. RENTSCHLER El AL 2,

AHPLIFICATION SYSTEM FOR GLOW RELAY DEVICES Filed Dec. 7. 1928 ,2 aw WINVENTOR H. C .REN'rscHLER BY D.E. EN

ATTORNEY Patented Dec. 4, 1934 UNITED ST TES PATENT 1,982,829 F 1 CEAMPLIFICATIOhT-SYSTEM FOR GLOW RELAY DEVICES Pennsylvania ApplicationDecember 7, 1928, Serial No. 324,557

2 Claims.

This invention relates to electrical discharge devices of the gaseousconduction type employing a starting anode for initiating a dischargetherein in response to feeble electrical currents 5 and utilizing suchfeeble discharge to enable a main discharge having a relatively largecurrent, to be started. More particularly, the invention relates to asystem for operating such devices.

It is well known that the voltage required to initiate an electricaldischarge in a glow discharge device is higher than that required tomaintain the discharge once it has started.

Thus, for instance, in a negative glow discharge device employing spacedapart electrodes in a gaseous atmosphere and operating in the absence ofthermionic emission, by a proper choice of electrode materials,electrode spacing, gas pressure, etc., the discharge may be made tostart at potentials as low as 110 to 120 volts while the discharge oncestarted will continue to operate after the potential has dropped to aslow as from 85 to 90 volts.

- This diiference in starting and operating potential is due largely tothe high resistance imposed by the cathode dark space. Upon initiating adischarge in the devices this cathode resistance is broken down andpermits the discharge to be maintained at a voltage lower than thestarting potential or it enables another independent discharge to bestarted in the tube at a materially lower voltage than that required tostart the discharge, in the absence of the auxiliary discharge. It hasbeen found that there is adefinite and critical spacing of theelectrodes for a particular gas and a particular pressure thereof atwhich the voltage and current required to start a discharge in thedevice is a minimum. Moreover, whereas devices of this nature mayreadily carry current up to several hundred milliamperes, the 40 amountof current required to start the discharge may be exceedingly small,that is in the nature- Briefly the device consists of an envelope con-'talning a gaseous medium having a cathode of large area and a main anodeand an auxiliary or starting anode of small areas.

The main anode is positioned with respect to the cathode so that aconsiderably higher voltage is required to start a discharge betweensaid electrode and the cathode than is ordinarily available from thecircuit in which these electrodes are connected, whereas, the startinganode is diflerently spaced with respect to the cathode and may beconstructed of a'diflerent material from the main anode so that adischarge may be started between such starting anode and the cathode ata considerably lower voltage than that necessary to initiate the maindischarge.

The starting anode is positioned at the critical distance from thecathode, or from an extens-on of the cathode at which the minimumvoltage is required to start the discharge with-the particular gas atthe pressure-employed. The main anode is arranged at a greater distancefrom the cathode.

As a consequence of this construction, if a predeterminedvoltage isimpressed between the main anode and the cathode, somewhat lower thanthat necessary to initiate a discharge therebetween but suflicientlyhigh to maintain such a discharge after it is once started and if asecond source of potential is applied between the starting anode and thecathode of suflicient voltage to initiate a discharge between suchelectrodes in response to some external condition permitting only afeeble current to flow in the starting anode circuit, the main anodedischarge may be started upon the initiation of the discharge from thestarting anode.

With such a device the extremely feeble currents, obtained for instancefrom a photo-electric cell, which may be in the nature of a microampereor a few micro-amperes, or even less produced in the circuit includingthe starting anode which, for convenience, is termed the in-put circuit,will initiate a discharge in the main anode circuit or out-put circuitof several hundred milliamperes which is sufficient to operate asensitive relay. However, when. such a sensitive glow-relay tube isoperated with high current out-put, near the limits of the tube, thetube is likely to become heated and its sensitivity and reliabilitydecreased. It is therefore, often necessary to operate such devices atlower out-put currents when extreme sensitivity is required, than thatnecessary to directly operate heavy mechanical relays.

One of the objects of the present invention is, therefore, to provide asystem employing sensitive glow-relay tubes of the nature described inwhich large out-put currents may be obtained without impairing thesensitivity of the system.

A further object is to provide an amplifying system for increasing thecurrent obtained from a glow-relay tube.

Other objects and advantages will appear hereinafter.

In accordance with our invention we operate a starting anode tube orglow-relay in response to feeble electric currents, such as those obtained from a photo-electric cell subjected-to light variations and weemploy the out-put cur-. rent obtained from the main anode circuit ofsuch a tube to supply the in-put current for one or more less sensitivestarting anode tubes of larger out-put capacity.

These amplifying tubes may be connected in parallel and supply arelatively heavy out-put current for directly operating mechanicalrelays or switches for setting into operation any desired electricalapparatus.

In order that the invention may be more fully understood reference willbe had to the accompanying drawing in which the single figureillustrates an electrical system employing our starting anode tubes.

In the drawing the current obtained from a photo-electric cell 1 isemployed to create a discharge through a starting anode tube 2 which inturn supplies current for setting into operation a pair of lesssensitive starting anode tubes 3 and 4 of greater out-put capacity whichare connected electrically in parallel. The current obtained from thetubes 3 and 4 is used to operate an electrical switch 5 for supplyingcurrent to a bank of lamps 6. The current for operating these devices isobtained froni a 110 volt A. 0. line 7.

The cathode 8 of the photo-electric cell is connected with a wire 9 tothe starting anode 10 of the glow-relay 2, the cathode 11 of which has astarting tip or extension 12 projecting into close proximity to thestarting anode 10. The cathode 11 is joined through the conductor 13 toone side of the line '7, the opposite side of which is connected throughthe conductor 14 with the anode 15 of the photo-electric cell 1.

Small currents flowing through the photoelectric cell in response to anincrease in illumination of the photo-electric cell, create a dischargebetween the starting anode 10 and the cathode 11. This discharge causesthe tube to break down and a heavier current discharge to be startedbetween the main anode 16 of the glow relay tube, which is connected toone side of the line 7 through the primary of a transformer 1'7, and thecathode 11 which is connected to the opposite side of the line.

The out-put current obtained from the glowrelay tube 2 is utilized tosupply the in-put current to the starting anodes of the amplifying tubes3 and 4. ondary 19 of the transformer 17 is connected to the cathodes 20of each of the amplifying tubes and the opposite terminal 21 of thesecondary 18 is connected to each of the starting anodes 22 of theamplifying tubes through suitable resistance 23 so that a dischargeoccurs in the amplifying tubes, between the starting anode and thecathode, in response to the discharge in the out-put circuit of thefirst relay tube 2. The cathodes 20 of the amplifying tubes areconnected to the line 7 by the conductor 24 and the main anodes 25 ofthese tubes are connected ,to the opposite side of the line 7 throughthe conductor 26 and the winding 27 of the switch 5, so that uponinitiation of the auxiliary discharge in these tubes the main dischargewill start and supply a relatively heavy current for operating theswitch 5. The switch 5 controls the current to a bank of lamps 6.

With the arrangement shown. the small current of a fraction of amicro-ampere or more, produced in the photo-electric cell 1 may beutilized to initiate the discharge through the first sensitive startinganode tube and the out-put current obtained from such tube utilized toinitiate the discharge in the less sensitive amplifying starting anodetubes to supply a heavy current for directly operating the switch 2'1.

It is obvious of course that various changes may One terminal 18 of thesec-' be made in the electrical connections for operating the amplifyingtubes by the current obtained from the tube 2 and the current ,obtainedfrom the amplifying tube may be utilized in various manners and we donot desire to be limited to the specific electrical connections shownand described except in accordance with the appended claims.

The system described may be utilized to control the illumination inoflices, factories, street lighting systems, etc., to automaticallylight and extinguish the lights in accordance with definite illuminatingconditions. For instance, if the photo-electric cell 1 is subjected toincreasing daylight illumination and the photo-electric cell is adjustedto permit a predetermined current to flow therethrough sufficient toinitiate a discharge in the relay tubes 2, when the daylightillumination is sufiicient for the purpose required, the amplifledcurrent obtained from the amplifier tubes 3 and 4 will open the switch 5and turn oil the lamps 6. When the day-light illumination decreasesbelow normal, the current flowin the photo-electric cell 1 becomes toosmall to maintain the discharge in the relay tube 2 and as a consequencethe windi 27 becomes de-energized; allowing the switch 5 to close andthe lamps to be lighted.

What is claimed is:

1. An electric system including a glow relay tube of the starting anodetype having an envelope, a gas, a cathode, a starting anode and a mainanode therein, comprising a starting circuit including a source ofpotential, the starting anode and the cathode of said tube and aradiation responsive means for controlling current flow between saidstarting anode and cathode, an output circuit including a source ofpotential, said main anode and cathode, a third circuit magneticallycoupled with said output circuit, said third circuit including thestarting anode and cathode of a second relay tube having a higher outputcapacity than said first mentioned tube, a fourth circuit including saidcathode and a main anode of said second relay tube and actuable meansassociated with said fourth circuit and adapted to be actuated uponcurrent fiow through said fourth circuit, said first mentioned tubebeing sensitive and said secondtube being less sensitive than said firstmentioned tube.

2. An electric system including a glow relay tube of the starting anodetype having an envelope, a gas. a cathode, a starting anode and a mainanode-therein, comprising a starting circuit including a source ofpotential, the starting anode and the cathode of said tube and aradiation responsive means all in series, an output circuit includingsaid source of potental, said main anode and said cathode of said tubeand the primary winding of a transformer in series, a third circuitincluding the starting anode and the cathode of a second glow relay tubeof the starting anode type, and, also a secondary 01 said transformer, afourth circuit including'thi. oathode and main anode of said second tubeand said source of potential and adapted to carry audicient current toactuate external means, said second tube having a higher output capacitythan said first tube and actuable means associated with said outputcircuit, said first mentioned tube being sensitive and said secondtubebeing less sensitive than said first mentioned tube.

HARVEY c. RaN'rscnLna. DONALD E. HENRY.

